Attenuated cortisol response to alcohol in heavy social drinkers.

Individual differences in response to stress may play a role in the development and maintenance of addictive behaviors. While there is evidence that people with a biological family history for alcoholism have a blunted cortisol response to alcohol, data are lacking in other at-risk subgroups, such as heavy social drinkers. The present study examined salivary cortisol response to administration of 0.0, 0.4 (2 drink equivalent), and 0.8 g/kg (4 drink equivalent) alcohol in two groups of social drinkers: heavy drinkers (n=32) and light social drinkers (n=23). The study was conducted double-blind and drink-order was counterbalanced between groups. Salivary cortisol and subjective measures were obtained at predrink baseline, and 15, 45, 105, and 165 min after beverage consumption. Results showed a significant groupxdosextime interaction (p<0.005), with alcohol (0.8 g/kg) producing an attenuated cortisol response in heavy drinkers compared to the light drinkers during the declining phase of the BAC. This outcome remained even after controlling for the effects of smoking status, family history of alcoholism, sex, and negative affect ratings during the session. Neither placebo nor the lower dose of alcohol significantly increased cortisol levels. In sum, a relatively high dose of alcohol produced a smaller increase in cortisol in heavy drinkers compared to light drinkers. The reduced cortisol reactivity in the heavier drinkers is consistent with reports that individuals at risk for alcoholism are hyporesponsive to physical and psychological stress. Further research may help determine whether alteration in cortisol response to alcohol is a biological marker of the propensity to abuse alcohol.